/*
 *  (C) Copyright 2008 Insula Tecnologia da Informacao Ltda.
 * 
 *  This file is part of Vulcano.
 *
 *  Vulcano is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Vulcano is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with Vulcano.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.openinsula.vulcano.core.command;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.util.Assert;

/**
 * @author Eduardo R Danielli
 *
 * @param <T> Object type
 * @param <R> Return type
 */
public abstract class SingleObjectCommand<T,R> implements Command<R> {
	
	protected final Log logger = LogFactory.getLog(getClass());
	
	private T object;
	
	public SingleObjectCommand(final T object) {
		setObject(object);
	}
	
	protected final void setObject(final T object) {
		boolean isNullAllowed = isNullAllowed();
		
		if (logger.isDebugEnabled()) {
			logger.debug("isNullAllowed: " + isNullAllowed);
		}
		
		if (!isNullAllowed) {
			Assert.notNull(object, "object cannot be null, as defined by isNullAllowed()");
		}
		
		this.object = object;
	}
	
	protected final T getObject() {
		return object;
	}
	
	protected boolean isNullAllowed() {
		return false;
	}

}
